Abstract:
The invention relates to a method for operating a high pressure lamp, where an alternating lamp current (2) is supplied to the lamp. To improve the light-arc stability and to decrease dissipation power in the circuit arrangement, the absolute value of said lamp current (2) is substantially constant, and said alternating lamp current (2) is pulse-width modulated, whereby the pulse-width ratio between a pulse-width of a positive pulse and a pulse-width of a negative pulse is modulated. Also a circuit arrangement, a lamp current signal (2), and the use of these is disclosed.
Abstract:
The invention relates to a method for operating a high pressure lamp, where an alternating lamp current (2) is supplied to the lamp. To improve the light-arc stability and to decrease dissipation power in the circuit arrangement, the absolute value of said lamp current (2) is substantially constant, and said alternating lamp current (2) is pulse-width modulated, whereby the pulse-width ratio between a pulse-width of a positive pulse and a pulse-width of a negative pulse is modulated. Also a circuit arrangement, a lamp current signal (2), and the use of these is disclosed.
Abstract:
The invention relates to an image projector with a High-Intensity-Discharge HID lamp ( 112 ) and a method of operating it. Such lamps have the disadvantage that their voltaic arc jumps back and forth between different positions at unforeseeable times during operation. This so-called arc jumping has the effect of changing the brightness, i.e. the overall brightness and/or the brightness distribution of the light emitted by the HID lamp ( 112 ). For the viewer of an image projected with such a projector, this effect appears as a jolt of this projected image. To avoid such effects for the viewer, it is first proposed according to the invention that changes in the brightness of the light in the image projector's beam path are detected. As soon as a change in brightness caused by an arc jump has been detected, this brightness is reset to a brightness detected at a moment t- 2 before the arc jump, in order subsequently to convert it during a predetermined time interval T to the brightness resulting from the arc jump. This resetting must occur so soon after the arc jump, and the conversion so slowly, that the changes in the brightness of the light incident on a picture screen device ( 118 ) resulting from the arc jump, the reset, and the conversion are not perceptible to the human eye.
Abstract:
A gas discharge lamp (10) for emitting ultraviolet light and an operating method is provided comprising a discharge vessel (12) comprising a vessel volume V at least partiallyfilled with a gas and/or a salt for providing an illuminating atmosphere for a discharge arc, a first electrode (14) ending in the discharge vessel (12), a second electrode (16) ending in the discharge vessel (12) and a control unit (18) electrically connectable to an 5 electrical source and electrically connectable to the first electrode (14) and the second electrode (16) for providing the discharge arc between the first electrode (14) and the second electrode (16) due to an applied electrical power P, whereby the control unit (18) is adapted to operate the first electrode (14) and the second electrode (16) in a normal operating mode at a ratio r of the electrical power P to the vessel volume V, wherein r is 1176W/cm 3 =r=2647W/cm 3, particularly1618W/cm 3 =?r=2500W/cm 3 and preferred 2059W/cm 3 =r=2353W/cm 3. This leads to a small gas discharge lamp (10), which provides more ultravioletlight without a significantly shortened lifetime.
Abstract translation:提供一种用于发射紫外线的气体放电灯(10)和操作方法,其包括放电容器(12),其包括至少部分填充有用于提供放电电弧的照明气氛的气体和/或盐的容器容积V, 结束于放电容器(12)的第一电极(14),终止于放电容器(12)的第二电极(16)和可电连接到5个电源并可电连接到第一电极的控制单元 (14)和第二电极(16),用于由于施加的电功率P在第一电极(14)和第二电极(16)之间提供放电电弧,由此控制单元(18)适于操作第一 电极(14)和第二电极(16)以正常操作模式以电功率P与容器体积V的比率r,其中r为1176W / cm 3 = r = 2647W / cm 3,特别是166W / cm 3 =Δr= 2500W / cm 3,优选2059W / cm 3 = r = 2353W / cm 3 导致小的气体放电灯(10),其提供更多的紫外线,而不会显着缩短寿命。
Abstract:
The invention describes a method of driving an arc-discharge lamp (1), which method comprises the steps of detecting a mechanically induced fluctuation in luminous flux of the lamp (1) occurring as a result of a physical displacement of the discharge arc (2), determining a characteristic (43, 51, 63) of the mechanically induced fluctuation in luminous flux of the lamp (1), and adjusting the lamp power on the basis of the determined characteristic (43, 51, 63) to suppress the mechanically induced fluctuation in luminous flux of the lamp (1). The invention further describes a driver (3) for an arc-discharge lamp (1), which driver comprises a detecting means (40, 50, 60) for detecting a mechanically induced fluctuation in luminous flux of the lamp (1) occurring as a result of a physical displacement of the discharge arc (2), a determination unit (42, 50, 62) for determining a characteristic (43, 51, 63) of the mechanically induced fluctuation in luminous flux of the lamp (1); and an adjustment unit (8) for adjusting a lamp power (Pc) on the basis of the determined characteristic (43, 51, 63) to suppress the mechanically induced fluctuation in luminous flux of the lamp (1). The invention also describes a lighting assembly (9) comprising a high-intensity gas- discharge lamp (1) and such a driver (3) for driving the lamp (1) according to the inventive method.
Abstract:
The invention describes a method of driving a gas-discharge lamp (1) according to conditions in a specific region (R) of the lamp (1), which gas-discharge lamp (1) comprises a burner (2) in which a first electrode (4) and a second electrode (5) are arranged on either side of a discharge gap, which lamp (1) is realised such that the position (PCs) of a coldest spot during an AC mode of operation is in the vicinity of the first electrode (4), which method comprises the steps of initially driving the lamp (1) in the AC mode of operation; monitoring an environment variable of the lamp (1), which environment variable is indicative of conditions in a specific region (R) of the lamp (1); switching to a temporary DC mode of operation at a DC power value on the basis of the monitored environment variable, whereby the first electrode (4) is allocated as the anode; and driving the lamp (1) in the DC mode of operation until the monitored environment variable has returned to an intermediate environment variable threshold value (TDCAC). The invention also describes a gas-discharge lamp and a driver for a gas-discharge lamp.